The present invention relates to a filling apparatus and more particularly to a filling apparatus capable of continuous, sequential filling of a plurality of containers.
An apparatus of this type is used for filling containers, such as bags, with a predetermined weight of flowable material such as, for example, cereals, grain or rice.
An example of the Applicant""s prior apparatus of this type is shown in Australian Patent No. 551762. This apparatus includes a chute which toggles under the influence of counterweights between directing all the flowable material input stream to a first container or to a second container.
A disadvantage of this prior art apparatus is that the speed of the flowable material must be limited so that the weighing apparatus can terminate the flow of material entering a container upon reaching its predetermined weight, with reasonable accuracy, notwithstanding inflight material and flow rate variations.
It is an object of the present invention to substantially overcome or at least ameliorate the disadvantages of the prior art devices and more particularly to provide a faster and more efficient filling arrangement.
It is a further object of the present invention to provide a filling arrangement capable of continuous, sequential filling of a plurality of containers.
Accordingly, in a first aspect, the present invention provides an apparatus for filling a plurality of containers with flowable material, the apparatus including:
a plurality of container filling stations arranged in a sequence; and a fixed flow divider located between one filling station and the next filling station in the sequence; and
a material guide for flow of flowable material,
wherein the apparatus includes means to move the material guide relative to the filling stations or vice versa so that the apparatus is capable of adopting:
a first rest position in which all the flow of flowable material is guided to one of the container filling stations;
an intermediate rest position in which the flow of flowable material is divided between the one container filling station and the next container filling station in the sequence; and
a second rest position in which the flow of flowable material is guided to the next container filling station.
The flowable material is preferably grain, cereal or rice.
There may be two or more container filling stations. When there are more than two filling stations, preferably these are arranged in a loop, such as a circle, so that containers may be filled in a continuous manner, one after the other. In this embodiment, movement of the material guide relative to the filling stations, or vice versa, can be effected in one direction only, with an empty container being placed at an appropriate filling station ahead of flow from the material guide reaching that filling station, and with filled containers being removed sequentially after filling. In this embodiment, it is preferred that the material guide is stationary and the filling stations travel past the material guide, by means of a conveyer belt, for example.
Alternately, the sequence of container filling stations may have a start and a finish point, rather than forming a loop. This, of course, will be the case if there are only two filling stations. Even with three or more filling stations, it is within the scope of this invention that, once the containers at the filling stations have been filled, the apparatus is designed to move back to the start point and repeat the performance. In this embodiment, while either the material guide or the filling stations may move, it is preferred that the filling stations remain stationary and the material guide moves.
Desirably, at the intermediate rest position 10% of the flow of flowable material is directed substantially to the one container filling station and 90% of the flow of flowable material is directed substantially to the next container filling station.
In one preferred embodiment, the material guide is a chute adapted to pivot about a substantially vertical axis between the first and second positions. The chute preferably includes an inclined base and two substantially vertical side walls. The base is preferably upwardly convex and includes corrugations for spreading the material flow across the width of the base.
In other embodiments, the material guide is a vibrating tray, or an auger fed nozzle which pivots in a substantially horizontal plane, or a gravity fed nozzle mounted beneath a flexible tube for pivoting in a substantially vertical plane.
The material guide may be, in fact, more than one guide, which can be useful when the flowable material has a tendency to stick together or to stick to the guide. If there is more than one material guide they may be controlled (see below) independently. For example, where there are two material guides, the first may direct a larger proportion of the flowable material while the second directs the remainder.
It is to be understood that the means moving the material guide relative to the filling stations, or moving the filling stations relative to the material guide, may be any suitable means, one of which is described in connection with an embodiment in the drawings, below.
The apparatus preferably includes weighing devices to weigh the amount of material in each of the containers. When it is the material guide which moves, the apparatus preferably also includes a control system adapted to cause moving of the material guide between the first, intermediate and second rest positions. In a sophisticated version of the invention, the control system causes such movement in response to the weight of material in each of the containers.
The control system (which may also be used when the filing stations move) may be pneumatically driven. It also preferably includes fine adjustment means capable of adjusting the portion of flow of flowable material into the first or next container to a fine degree. For example, in one embodiment, the fine adjustment may cause the input to be divided so that 99% flows into one container while 1% flows into the other. The fine adjustment means preferably takes the form of a wheel adapted to cause the chute to move in small increments towards the first or second container.
In a second aspect, the present invention provides a method for filling a plurality of containers using the apparatus of the invention, said method including the steps of:
(1) directing all of the flow of flowable material into a first container until it is filled to a first predetermined weight;
(2) directing a portion of the flow of flowable material into each of the first container and a second container adjacent the first container until the first container is substantially full;
(3) directing all of the flow of flowable material into the second container until it is filled to a second predetermined weight;
(4) directing a portion of the flow of flowable material into each of the second container and a third container adjacent the second container; and
(5) directing a portion of the flow of flowable material into each of the third and second containers until the second container is substantially full.
Preferably, steps (1) to (5) are repeated to continuously fill the plurality of containers until a predetermined number of containers is filled or the flow of flowable material is exhausted. The first and second predetermined weights are preferably substantially equal. Desirably, the flow at step (2) is directed 10% to the first container and 90% to the second container. At step (5) the flow is desirably directed 90%, 10% to the third and second containers respectively.